System and method for positioning a slider of a reversing valve

ABSTRACT

A system and method for positioning a slider of a reversing valve. A method includes receiving a command for operating a reversing valve in a first mode, a second mode or a third mode. The reversing valve comprises a first tube, a second tube, a third tube, and a fourth tube. The method further describes determining a tonnage profile for refrigerant to flow in the reversing valve. The method further describes communicating the command and the tonnage profile to a stepper motor and linearly moving a lead screw based on the command and the tonnage profile to position a slider on the second tube and the third tube in the second mode and the third mode or on the third tube and the fourth tube in the first mode.

FOREIGN PRIORITY

This application claims priority to Indian Patent Application No.201911048669, filed Nov. 27, 2019, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which in its entiretyare herein incorporated by reference.

TECHNICAL FIELD

The present invention generally relates to heat pumps. Moreparticularly, the invention relates to a system and a method forpositioning a slider of a reversing valve in the heat pumps.

BACKGROUND

In earlier times, a heater device was used to heat up a particulararea/room in winters and a cooler device was used for cooling the samearea in summers. The heater device and the cooler device had to beseparately bought and installed in the same area to perform separatefunctioning. With the developments in the technology, heat pumps weredeveloped that can be used for heating as well as cooling the same area.

In order to use the same heat pump for heating operation, defrostingoperation as well as cooling operation, a reversible valve is used inthe heat pumps that can perform heating, defrosting, and coolingoperations one at a time. Such reversible valve eliminates therequirement of using separate devices for heating, defrosting andcooling operations. In particular, the reversible valve has a solenoidvalve to shift the reversible valve for reversing the operation.However, the solenoid valve needs to energized all the time based onrequired operation thereby, resulting in wastage of energy. Further, thesolenoid valve relies upon optimal pressure differential between highand low sides of the heat pump that can be unreliable in some systems.Furthermore, the reversible valve sometimes fails to shift from theheating operation to cooling operation or vice-versa, or from defrostingoperation to heating operation and does not completely reverse theoperation. Moreover, the reversible valve also suffers leakage whilereversing operation. In addition, only one reversing valve can be usedfor each tonnage.

In view of the afore-mentioned problems in the existing reversiblevalve, there is a need of an efficient and effective system and methodfor eliminating the requirement of energizing a valve for both cooling,defrosting and heating operations. There is also a need of a valve thatcompletely reverses an operation. There is also a need of a valve thatdoes not fail to shift the operation. In order to solve problems in theexisting reversible valve, a system and a method are disclosed.

SUMMARY

Various embodiments of the invention describe a system for positioning aslider of a reversing valve in heat pump/s. The system comprises areversing valve adapted to operate in a first mode, a second mode or athird mode. Further, the reversing valve comprises a first tube, asecond tube, a third tube and a fourth tube. The system also comprises acontrol board adapted to receive a command for operating the reversingvalve in the first mode, the second mode or the third mode and determinea tonnage profile for refrigerant to flow in the reversing valve. Also,the refrigerant flows in a first flow in the first mode or in a secondflow in the second mode or in the second flow in the third mode. Thecontrol board is adapted to communicate the command and the tonnageprofile for the refrigerant to a stepper motor. The stepper motor isadapted to linearly move a lead screw based on the command and thetonnage profile to position a slider on the second tube and the thirdtube in the second mode or on the third tube and the fourth tube in thefirst mode or on the second tube and the third tube in the third mode.

In an embodiment of the invention, the tonnage profile for refrigerantis determined based on a temperature defined by a user.

In another embodiment of the invention, the slider is variablypositioned at a first position for a first tonnage profile, at a secondposition for a second tonnage profile and/or at a third position for athird tonnage profile.

In yet another embodiment of the invention, the stepper motor is adaptedto perform a first number of steps for positioning the slider at a firstposition, a second number of steps for positioning the slider at asecond position and/or a third number of steps for positioning theslider at a third position.

In another embodiment of the invention, the stepper motor is adapted todetermine an incorrect position of the slider based on a currentlocation of the slider, wherein the control board is adapted to verifythe incorrect position of the slider with respect to a programmedlocation of the slider and is adapted to provide a command to thestepper motor to move the slider to a desired location.

In still another embodiment of the invention, the lead screw is linearlymoved in an inward direction in the second mode or the third mode toposition the slider on the second tube and the third tube.

In a different embodiment of the invention, the lead screw is linearlymoved in an outward direction in the first mode to position the slideron the third tube and the fourth tube.

In yet another embodiment of the invention, the first mode is a heatingmode and the second mode is a cooling mode and the third mode is adefrost mode.

In another embodiment of the invention, the first tube is a compressordischarge tube. Also, the first tube is positioned at a first surface ofthe reversing valve.

In an embodiment of the invention, the second tube, the third tube, andthe fourth tube are positioned at a second surface of the reversingvalve.

In yet another embodiment of the invention, the second tube acts as acondenser tube, the third tube acts as a compressor return tube, and thefourth tube acts as an evaporator tube in the first mode.

In another embodiment of the invention, the second tube acts as anevaporator tube, the third tube acts as a compressor return tube, andthe fourth tube acts as a condenser tube in the second mode and/or inthe third mode.

In still another embodiment of the invention, the second tube isconnected to an indoor unit and the fourth tube is connected to anoutdoor unit in the first mode, in the second mode and/or in the thirdmode.

In a different embodiment of the invention, the refrigerant flows from acompressor to the first tube, from the first tube to the second tube andfrom the second tube to an indoor unit in the first flow. Further, therefrigerant flows from a compressor to the first tube, from the firsttube to the fourth tube and from the fourth tube to an outdoor unit inthe second flow.

In an embodiment of the invention, the slider is a C-shaped slider or aU-shaped slider.

Various embodiments of the invention describe a method for positioning aslider of a reversing valve in heat pump/s. The method comprises thestep of receiving by a control board, a command for operating areversing valve in a first mode, a second mode or a third mode. Thereversing valve comprises a first tube, a second tube, a third tube anda fourth tube. The method also comprises the step of determining by thecontrol board, a tonnage profile for refrigerant to flow in thereversing valve. Also, the refrigerant flows in a first flow in thefirst mode or in a second flow in the second mode and in the second flowin the third mode. The method further comprises the step ofcommunicating the command and the tonnage profile for refrigerant to astepper motor. Accordingly, the stepper motor linearly moves a leadscrew based on the command and the tonnage profile to position a slideron the second tube and the third tube in the second mode or on the thirdtube and the fourth tube in the first mode or on the second tube and thethird tube in the third mode.

In another embodiment of the invention, the slider is variablypositioned at a first position for a first tonnage profile, at a secondposition for a second tonnage profile and/or at a third position for athird tonnage profile.

In yet another embodiment of the invention, the lead screw is linearlymoved in an inward direction in the second mode or in the third mode toposition the slider on the second tube and the third tube and the leadscrew is linearly moved in an outward direction in the first mode toposition the slider on the third tube and the fourth tube.

In still another embodiment of the invention, the first mode is aheating mode, the second mode is a cooling mode and the third mode is adefrost mode.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A depicts an assembled view of an exemplary reversing valve andFIG. 1B depicts an exploded view of the exemplary reversing valveaccording to an exemplary embodiment of the invention.

FIG. 1C depicts a top view of an exemplary flow diverter of a reversingvalve, FIG. 1D depicts a cross-sectional front view of the exemplaryflow diverter, FIG. 1E depicts a bottom view of the exemplary flowdiverter, FIG. 1F depicts a side view of the exemplary flow diverter,and FIG. 1G depicts a cross-sectional front view of the exemplaryreversing valve, according to an exemplary embodiment of the invention.

FIG. 2 depicts an exemplary system architecture with a reversing valveoperating in a first mode according to an exemplary embodiment of theinvention.

FIG. 3 depicts an exemplary system architecture with a reversing valveoperating in a second mode or in a third mode according to an exemplaryembodiment of the invention.

FIG. 4A depicts an exemplary first position of a slider for a firsttonnage profiles in a first mode, FIG. 4B depicts an exemplary secondposition and third position of a slider for a second or third tonnageprofiles in a first mode, FIG. 4C depicts an exemplary first position ofa slider for a first tonnage profiles in a second mode, and FIG. 4Ddepicts an exemplary second position and third position of a slider fora second or third tonnage profiles in a second mode according to anexemplary embodiment of the invention.

FIG. 5 depicts an exemplary flowchart illustrating a method to performthe invention according to an exemplary embodiment of the invention.

Corresponding reference numerals indicate corresponding parts throughoutthe drawings.

DETAILED DESCRIPTION

Described herein is the technology with a system and a method forpositioning a slider of a reversing valve in heat pump/s. The reversingvalve may comprise a first tube, a second tube, a third tube and afourth tube. The reversing valve may be connected with a compressor, anindoor unit and an outdoor unit through one or more tubes. Further, thereversing valve may operate either in a first mode or in a second modeor in a third mode based on a command. The command may be provided by auser through a thermostat for operating the reversing valve in the firstmode or in the second mode or in the third mode. The command may bereceived by a control board and the control board may determine atonnage profile for refrigerant to flow through the reversing valve.Based on the command and the tonnage profile for refrigerant, a steppermotor moves a lead screw to position a slider on the second tube and thethird tube when the reversing valve operates in the second mode or onthe third tube and the fourth tube when the reversing valve operates inthe first mode or on the second tube and on the third tube when thereversing valve operates in the third mode. In specific, the steppermotor may be programmed in such a way that the stepper motor moves thelead screw linearly to place the slider at various positions based onthe tonnage profile for refrigerant in the first mode or the second modeor the third mode.

As used herein, the reversing valve may be adapted to control a flow ofrefrigerant through the reversing valve based on the first mode or thesecond mode or the third mode. The first mode may be a heating mode andthe second mode may be a cooling mode and third mode may be a defrostmode. When the reversing valve operates in the first mode, therefrigerant flows in a first flow and when the reversing valve operatesin the second mode, the refrigerant flows in a second flow and when thereversing valve operates in the third mode, the refrigerant flows in thesecond flow. The details of flow of the refrigerant in the reversingvalve operating in the first mode or the second mode or the third modehave been explained in detail below. The reversing valve may be anyslide-type reversing valve that is well known in the art. When thereversing valve is used in variable speed units and at variable flows,the tonnage profile may vary.

As used herein, the control board may be an electronic circuitry or aprinted circuit board communicably coupled and/or attached with thereversing valve and/or a thermostat. The control board may be presentoutside the reversing valve. The control board may also be communicablycoupled with the thermostat to receive a command. The command may beprovided by a user to operate the reversing valve either in the firstmode or the second mode or the third mode. The control board may furtherbe communicably coupled and/or attached with a stepper motor.

As used herein, the stepper motor may be communicably coupled and/orattached with the reversing valve and or the control board. The steppermotor may be present outside the reversing valve. Further, the steppermotor may be programmed in such a way that the stepper motor may move alead screw inside the reversing valve to position a slider. The steppermotor may be any stepper motor that is well known in the art.

FIG. 1A depicts an assembled view 100A of an exemplary reversing valve102 according to an exemplary embodiment of the invention. As depictedin FIG. 1A, the reversing valve 102 may have a first surface 104 and asecond surface 108. Further, the reversing valve 102 may comprise afirst tube 106, a second tube 110, a third tube 112, and a fourth tube114. As can be seen, the first tube 106 may be positioned at the firstsurface 104 of the reversing valve 102. Also, the second tube 110, thethird tube 112, and the fourth tube 114 may be positioned at the secondsurface 108 of the reversing valve 102. The reversing valve 102 alsocomprises a stepper motor 118 and a lead screw 120 to position a slider(not shown) on any two tubes of the reversing valve 102. Also, a mount138 for attaching the stepper motor may be connected or attached withthe reversing valve 102.

FIG. 1B depicts an exploded view 100B of the exemplary reversing valve102 according to an exemplary embodiment of the invention. In thisexploded view 100B, the reversing valve 102 comprises a stepper motor118, a lead screw 120 communicably coupled with the stepper motor 118, amount 138 for the stepper motor 118 and attached with the reversingvalve 102, a nut 136 for the lead screw 120, a flow diverter 134 todivert or guide refrigerant in the reversing valve 102, a cap 140 toenclose/cover a side of the reversing valve 102 and a pin 142 to beinserted in the cap 140. The flow diverter 134 may be inserted insidethe reversing valve 102.

FIG. 1C depicts a top view of an exemplary flow diverter 134 of areversing valve 102 according to an exemplary embodiment of theinvention. In this top view, a first mode tube and a second mode tubecan be seen. The first mode tube of the flow diverter 134 may be usedwhen the reversing valve 102 operates in a first mode. Similarly, thesecond mode tube of the flow diverter 134 may be used when the reversingvalve 102 operates in a second mode. The first mode tube and the secondmode tube of the flow diverter 134 may be used to make the refrigerantflow in the reversing valve 102 as per the mode in which the reversingvalve 102 is operating.

FIG. 1D depicts a cross-sectional front view of the exemplary flowdiverter 134 according to an exemplary embodiment of the invention. Inthis cross-sectional front view, along with the first mode tube and thesecond mode tube of the flow diverter 134, a slider 116 can be seen.Further, the slider 116 may be positioned on any two tubes of thereversing valve 102 as per the mode in which the reversing valve 102 isoperating. This has been discussed in details in FIG. 2 and FIG. 3below.

FIG. 1E depicts a bottom view of the exemplary flow diverter 134according to an exemplary embodiment of the invention. In this bottomview, the first mode tube and the second mode tube may be positioned attwo opposite extreme ends of the flow diverter 134. Also, the slider 116may be present in between the first mode tube and the second mode tubeof the flow diverter 134 in the reversing valve 102.

FIG. 1F depicts a side view of the exemplary flow diverter 134,according to an exemplary embodiment of the invention. The side view ofthe flow diverter 134 has a pin and the cap 140 (as shown in FIG. 1B)may be used to cover the side view of the exemplary flow diverter 134.FIG. 1G depicts a cross-sectional front view of the exemplary reversingvalve 102, according to an exemplary embodiment of the invention.

FIG. 2 depicts exemplary system architecture 200 with a reversing valve102 operating in a first mode according to an exemplary embodiment ofthe invention. Based on a mode of operation of the reversing valve 102,the stepper motor 118 may accordingly move the lead screw 120 toposition the slider 116 on any two tubes of the reversing valve 102.Moreover, as depicted, a thermostat 130 and/or the indoor unit 124 maybe placed inside a building/home 128. The indoor unit 124 may be adaptedto provide heating inside the building/home 128.

A user (not shown) may select an option in the thermostat 130 to operatethe reversing valve 102 in a first mode. For this, the user may use asoft button or hard button provided in an interface of the thermostat130 to give a command for operating the reversing valve 102 in the firstmode. In an exemplary embodiment, the first mode may be a heating mode.Before the user provides the command, heat pump of the reversing valve102 may be powered-on for starting its functioning or the reversingvalve 102 was already operating in a cooling mode (i.e. a second mode)and may provide a command for mode reversal. In an exemplary embodiment,the command provided by the user may be G-code commands that are used inreal time to build a system with dynamic behavior to have precisemovements to a lead screw. When the user provides the command, thethermostat 130 may transmit the command to a control board 132 through awired network or a wireless network. The control board 132 may becommunicably coupled or attached with the thermostat 130 and thereversing valve 102. The control board 132 may be present inside oroutside the building/home 128.

When the control board 132 receives the command from the thermostat 130to operate the reversing valve 102 in the first mode, the control board132 may determine a tonnage profile for refrigerant to flow in thereversing valve 102. For this, the tonnage profile for refrigerant isdetermined by the control board 132 based on a temperature defined bythe user and/or a temperature inside the building/home 128. In specific,the user may define the temperature based on number of people/occupantspresent in the building/home 128. For an instance, the user may vary thetonnage by varying the refrigerant for a 3 tons heat pump with only oneoccupant in the building/home 128. If there are multiple occupants inthe building/home 128 which may exceed temperature, then the system 100may decide to run at full load condition, depending upon the heatgenerated by multiple occupants the building/home 128. In an exemplaryembodiment, the control board 132 may request the thermostat 130 toprovide a current temperature inside the building/home 128. In anotherexemplary embodiment, the control board 132 may determine a currenttemperature inside the building/home 128. In another exemplaryembodiment, the tonnage profile for the refrigerant may be determinedbased on a product number and a type of the control board 132. For aninstance, if the product number is 24ABB360A0000101, the tonnage profilewill be 3 Ton unit. Also, by using the control board 132 of 3 tons withvariable speed, then the 3 Ton unit may be downgraded to function as 2.5T, 2 T and 1.5 T etc. Furthermore, the 3 Ton control board 132 can onlywork under full load condition and cannot be upgrade to next highertonnages. In other words, the control selected for 3 T will be veryspecific to 3 T and for down-gradable tonnages only.

After the control board 132 determines the current temperature insidethe building/home 128, the control board 132 may accordingly determine atonnage profile for the refrigerant to flow into the reversing valve102. The control board 132 may determine a first tonnage profile, asecond tonnage profile or a third tonnage profile. The control board 132may determine the first tonnage profile when a difference between thecurrent temperature inside the building/home 128 and a pre-definedheating temperature threshold is low. Similarly, the control board 132may determine the second tonnage profile when a difference between thecurrent temperature inside the building/home 128 and a pre-definedheating temperature threshold is nominal. Likewise, the control board132 may determine the third tonnage profile when a difference betweenthe current temperature inside the building/home 128 and a pre-definedheating temperature threshold is high. Then, the control board 132 maycommunicate the command to operate the reversing valve 102 in the firstmode and the determined tonnage profile to the stepper motor 118. In anexemplary embodiment, the pre-defined heating temperature threshold maybe defined by the user of the thermostat 130 and may be the temperaturethat is desired to be maintained inside the building/home 128.

When the stepper motor 118 receives the command and the determinedtonnage profile, the stepper motor 118 may linearly move the lead screw120 based on the command and the tonnage profile. In particular, thestepper motor 118 may be programmed in such a manner that the steppermotor 118 may move the lead screw 120 to position the slider 116 at afirst position when the control board 132 determines the first tonnageprofile. Likewise, the stepper motor 118 may move the lead screw 120 toposition the slider 116 at a second position when the control board 132determines the second tonnage profile. Also, the stepper motor 118 maymove the lead screw 120 to position the slider 116 at a third positionwhen the control board 132 determines the third tonnage profile. Thisembodiment of the present invention provides a technical advantage ofeliminating the requirement of continuously energizing a valve forheating and providing complete reversal of from cooling mode to heatingmode. Also defrosting mode, when control board 132 sends command, whendesired.

In an exemplary embodiment, the slider 116 may be a C-shaped slider or aU-shaped slider or any such shape that offers lesser pressure dropand/or smooth flow. Further, in the first mode and as depicted in FIG.2, the first tube 106 of the reversing valve 102 may be connected with adischarge port of a compressor 122. The second tube 110 may be connectedwith an indoor unit 124, the third tube 112 may be connected with areturn port of a compressor 122 and the fourth tube 114 may be connectedwith an outdoor unit 126. Furthermore, in the first mode, the steppermotor 118 may move the lead screw 120 to position the slider 116 on thethird tube 112 and the fourth tube 114 as shown in FIG. 2. Also, thestepper motor 118 may linearly move the lead screw 120 in an outwarddirection from the reversing valve 102 to position the slider 116 on thethird tube 112 and the fourth tube 114. The determination of the tonnageprofile and the positioning of the slider 116 with respect to thetonnage profile have been explained in greater details below withexamples in exemplary Table 1 and also depicted in FIG. 4A and FIG. 4Bbelow.

TABLE 1 Heating Mode Current Pre-defined Opening of Temperature Heatingeach tube in Inside Temperature Tonnage Flow of Position of millimeters(mm) Building threshold Profile Refrigerant Slider by moving Slider 24°Celsius 30° Celsius First 1.5 tons to First 12 mm opening Tonnage 2 tonsPosition for each tube Profile 12° Celsius 30° Celsius Second 3 tons toSecond 12 mm opening Tonnage 4 tons Position for first tube Profile 106and 17.21 mm opening for other tubes 110, 112, 114 2° Celsius 30°Celsius Third 5 tons Third 12 mm opening Tonnage Position for first tubeProfile 106 and 17.21 mm opening for other tubes 110, 112, 114

As can be seen in Table 1 above, the first tonnage profile may bedetermined when the difference between the current temperature (i.e. 24°Celsius) inside the building/home 128 and the pre-defined heatingtemperature threshold (i.e. 30° Celsius) is low (i.e. 6° Celsius). Forthe first tonnage profile, the stepper motor 118 may move the lead screw120 to position the slider 116 at a first position on the third tube 112and the fourth tube 114. At the first position, the stepper motor 118may move the lead screw 120 to open each tube 106, 110, 112, 114 by 12mm so that the refrigerant may flow at the volume of 1.5 tons to 2 tons.Further, the second tonnage profile may be determined when thedifference between the current temperature (i.e. 12° Celsius) inside thebuilding/home 128 and the pre-defined heating temperature threshold(i.e. 30° Celsius) is nominal (i.e. 18° Celsius). For the second tonnageprofile, the stepper motor 118 may move the lead screw 120 to positionthe slider 116 at a second position on the third tube 112 and the fourthtube 114. At the second position, the stepper motor 118 may move thelead screw 120 to open first tube 106 by 12 mm and to open the secondtube 110, the third tube 112 and the fourth tube 114 by 17.21 mm so thatthe refrigerant may flow at the volume of 3 tons to 4 tons. Moreover,the third tonnage profile may be determined when the difference betweenthe current temperature (i.e. 2° Celsius) inside the building/home 128and the pre-defined heating temperature threshold (i.e. 30° Celsius) ishigh (i.e. 28° Celsius). For the third tonnage profile, the steppermotor 118 may move the lead screw 120 to position the slider 116 at athird position on the third tube 112 and the fourth tube 114. At thethird position, the stepper motor 118 may move the lead screw 120 toopen first tube 106 by 12 mm and to open the second tube 110, the thirdtube 112 and the fourth tube 114 by 17.21 mm so that the refrigerant mayflow at the volume of 5 tons. By determining the tonnage profile, thisembodiment of the present invention provides a technical advantage ofprecise/fine positioning of the slider 116 on the on third tube 112 andthe fourth tube 114 using the programmed stepper motor 118 and varyingthe flow of the refrigerant. Such variations in positioning of theslider 116 on the third tube 112 and the fourth tube 114 may help ineffective heating inside the building/home 128. Various other variationsin positioning the slider and relative movement of the lead screw arewithin the scope of the invention. In specific, the movement of the leadscrew 120 may be linear with the movement of the slider 116. Moreover,the openings of the tube for variable speed and variable flow units for1.5 T to 2 T, the variable flow rate will be 50%, 60% and 70% opening,whereas for the opening for variable speed and variable flow units for 3T to 5 T, the variable flow rate will be 50%, 60% and 70% opening.

Based on the tonnage profile and the command, the refrigerant may movein a first flow when the reversing valve 102 operates in the first mode.In particular, the refrigerant may discharge from the discharge port ofthe compressor 122 at a high pressure and may flow/enter in the firsttube 106 of the reversing valve 102. In an exemplary embodiment, thefirst tube 106 may act as a compressor discharge tube when therefrigerant enters in the first tube 106 from discharge port of thecompressor 122. From the first tube 106, the refrigerant may flow to thesecond tube 110 as the slider 116 is placed on the third tube 112 andthe fourth tube 114. In an exemplary embodiment, the second tube 110 mayact as a condenser tube. From the second tube 110, the refrigerant mayflow to the indoor unit 124 and then may pass to the outdoor unit 126.In an exemplary embodiment, the outdoor unit 126 may be an evaporatorthat converts the refrigerant from a liquid state to a gaseous state.From the outdoor unit 126, the refrigerant may enter the fourth tube 114and then from the fourth tube 114, the refrigerant may enter to thethird tube 112 through the slider 116. In an exemplary embodiment, thefourth tube 114 may act as an evaporator tube as the refrigerant getsevaporated. Then the refrigerant may exit the third tube 112 and may goback to the return port of the compressor 122. In an exemplaryembodiment, the third tube 112 acts as a compressor return tube as therefrigerant returns to the compressor 122.

FIG. 3 depicts exemplary system architecture 300 with a reversing valve102 operating in a second mode according to an exemplary embodiment ofthe invention. A user (not shown) may select an option in the thermostat130 to operate the reversing valve 102 in the second mode or in thethird mode. For this, the user may use a soft button or hard buttonprovided in an interface of the thermostat 130 to give a command foroperating the reversing valve 102 in the second mode or in the thirdmode. In an exemplary embodiment, the second mode may be a cooling modeand the third mode may be defrost mode. Before the user provides thecommand, heat pump of the reversing valve 102 may be powered-on forstarting its functioning or the reversing valve 102 was alreadyoperating in a heating mode (i.e. a first mode) and may provide acommand for mode reversal. When the user provides the command, thethermostat 130 may transmit the command to the control board 132 througha wired network or a wireless network.

When the control board 132 receives the command from the thermostat 130to operate the reversing valve 102 in the second mode or in the thirdmode, the control board 132 may determine a tonnage profile for therefrigerant to flow in the reversing valve 102. For this, the tonnageprofile for refrigerant is determined by the control board 132 based ona temperature inside building/home 128 and/or a temperature set by theuser. The control board 132 may determine a current temperature insidebuilding/home 128 as explained in FIG. 2 above. After the control board132 determines the current temperature inside the building/home 128,then the control board 132 may accordingly determine a tonnage profilefor refrigerant to flow in the reversing valve 102. The control board132 may determine a first tonnage profile, a second tonnage profile or athird tonnage profile. The control board 132 may determine the firsttonnage profile when a difference between the current temperature insidethe building/home 128 and a pre-defined cooling temperature threshold islow. Similarly, the control board 132 may determine the second tonnageprofile when a difference between the current temperature inside thebuilding/home 128 and a pre-defined cooling temperature threshold isnominal. Likewise, the control board 132 may determine the third tonnageprofile when a difference between the current temperature inside thebuilding/home 128 and a pre-defined cooling temperature threshold ishigh. Then, the control board 132 may communicate the command to operatethe reversing valve 102 in the second mode and the determined tonnageprofile to the stepper motor 118. In an exemplary embodiment, thepre-defined cooling temperature threshold may be defined by the user ofthe thermostat 130 and may be the temperature that is desired to bemaintained inside the building/home 128.

When the stepper motor 118 receives the command and the determinedtonnage profile, the stepper motor 118 may linearly move the lead screw120 based on the command and the tonnage profile. In particular, thestepper motor 118 may be programmed in such a manner that the steppermotor 118 may move the lead screw 120 to position the slider 116 at afirst position when the control board 132 determines the first tonnageprofile, at a second position when the control board 132 determines thesecond tonnage profile and a third position when the control board 132determines the third tonnage profile. Furthermore, in the second mode orin the third mode, the stepper motor 118 may move the lead screw 120 toposition the slider 116 on the second tube 110 and the third tube 112.Also, the stepper motor 118 may linearly move the lead screw 120 in aninward direction (as shown in FIG. 3) from the reversing valve 102 toposition the slider 116 on the second tube 110 and the third tube 112.As depicted in FIG. 3, in the second mode or in the third mode of thereversing valve 102, the first tube 106 of the reversing valve 102 maybe connected with a discharge port of a compressor 122, the second tube110 may be connected with the indoor unit 124, the third tube 112 may beconnected with the a return port of the compressor 122, and the fourthtube 114 may be connected with the outdoor unit 126. This embodiment ofthe present invention provides a technical advantage of eliminating therequirement of continuously energizing a valve for cooling and providingcomplete reversal from heating mode to cooling mode or to defrost mode.The determination of the tonnage profile and the positioning of theslider 116 with respect to the tonnage profile in the second mode or inthe third mode have been explained in greater details in exemplary Table2 below and also depicted in FIG. 4C and FIG. 4D below.

TABLE 2 Cooling Mode or Defrost Mode Current Pre-defined Opening ofTemperature Cooling each tube in inside Temperature Tonnage Flow ofPosition of millimeters (mm) Building threshold Profile RefrigerantSlider by moving slider 22° Celsius 18° Celsius First 1.5 tons to First12 mm opening Tonnage 2 tons Position for each tube Profile 30° Celsius18° Celsius Second 3 tons to Second 12 mm opening Tonnage 4 tonsPosition for first tube Profile 106 and 17.21 mm opening for other tubes110, 112, 114 40° Celsius 18° Celsius Third 5 tons Third 12 mm openingTonnage Position for first tube Profile 106 and 17.21 mm opening forother tubes 110, 112, 114

As can be seen in Table 2 above, the first tonnage profile may bedetermined when the difference between the current temperature (i.e. 22°Celsius) inside the building/home 128 and the pre-defined coolingtemperature threshold (i.e. 18° Celsius) is low (i.e. 4° Celsius). Forthe first tonnage profile, the stepper motor 118 may move the lead screw120 to position the slider 116 at a first position on the second tube110 and the third tube 112. At the first position, the stepper motor 118may move the lead screw to open each tube 106, 110, 112, 114 by 12 mm sothat the refrigerant may flow at the volume of 1.5 tons to 2 tons.Further, the second tonnage profile may be determined when thedifference between the current temperature (i.e. 30° Celsius) inside thebuilding/home 128 and the pre-defined cooling temperature threshold(i.e. 18° Celsius) is nominal (i.e. 12° Celsius). For the second tonnageprofile, the stepper motor 118 may move the lead screw 120 to positionthe slider 116 at a second position on the second tube 110 and the thirdtube 112. At the second position, the stepper motor 118 may move thelead screw 120 to open first tube 106 by 12 mm and to open the secondtube 110, the third tube 112 and the fourth tube 114 by 17.21 mm so thatthe refrigerant may flow at the volume of 3 tons to 4 tons. Moreover,the third tonnage profile may be determined when the difference betweenthe current temperature (i.e. 40° Celsius) inside the building/home 128and the pre-defined cooling temperature threshold (i.e. 18° Celsius) ishigh (i.e. 22° Celsius). For the third tonnage profile, the steppermotor 118 may move the lead screw 120 to position the slider 116 at athird position on the second tube 110 and the third tube 112. At thethird position, the stepper motor 118 may move the lead screw 120 toopen first tube 106 by 12 mm and to open the second tube 110, the thirdtube 112 and the fourth tube 114 by 17.21 mm so that the refrigerant mayflow at the volume of 5 tons. By determining the tonnage profile, thisembodiment of the present invention provides a technical advantage ofprecise/fine positioning of the slider 116 on the second tube 110 andthe third tube 112 using the programmed stepper motor 118 and varyingthe flow of the refrigerant. Such variations in positioning of theslider 116 on the second tube 110 and the third tube 112 may help ineffective cooling inside the building/home 128. In specific, themovement of the lead screw 120 may be linear with the movement of theslider 116.

Based on the tonnage profile and the command, the refrigerant may movein a second flow when the reversing valve 102 operates in the secondmode or in the third mode. In particular, the refrigerant may dischargefrom the discharge port of the compressor 122 at a high pressure and mayflow/enter in the first tube 106 of the reversing valve 102. In anexemplary embodiment, the first tube 106 may act as a compressordischarge tube as the refrigerant enters in the first tube 106 fromdischarge port of the compressor 122. From the first tube 106, therefrigerant may flow to the fourth tube 114 as the slider 116 is placedon the second tube 110 and the third tube 112. The indoor unit 124 maybe adapted to provide cooling inside the building/home 128. In anexemplary embodiment, the outdoor unit 126 may be a condenser thatconverts the refrigerant from a gaseous state to a liquid state. Fromthe indoor unit 124, the refrigerant may enter the second tube 110 andthen to the third tube 112 through the slider 116. In an exemplaryembodiment, the second tube 110 may act as an evaporator tube as therefrigerant gets evaporated. Then, the refrigerant may exit through thethird tube 112 and may goes back to the return port of the compressor122. In an exemplary embodiment, the third tube 112 may act as acompressor return tube as the refrigerant returns to the compressor 122.

The present invention encompasses the stepper motor 118 to be programmedin such a way that the positioning of the slider 116 using the leadscrew 120 is done in number of steps per revolution as performed by thestepper motor 118. For this, the number of steps per revolution to beperformed/taken by the stepper motor 118 to position the slider 116 maybe programmed. The stepper motor 118 may be programmed to perform/take afirst number of steps for positioning the slider 116 at the firstposition, a second number of steps for positioning the slider 116 at thesecond position and/or a third number of steps for positioning theslider 116 at the third position. For an instance, the stepper motor 118may be programmed to take 50 number of steps to position the slider 116at first position to open 12 mm diameter of each of the tubes. Also, thestepper motor 118 may be programmed to take 120 number of steps toposition the slider 116 at second position open 17.21 mm diameter of thethree tubes 110, 112, 114. Then, the stepper motor 118 may be programmedto take 200 number of steps to position the slider 116 at thirdposition.

The present invention further encompasses the stepper motor 118 and/orthe control board 132 may determine an error associated with themovement/position of the slider 116. For this, the stepper motor 118and/or the control board 132 may determine an incorrect position of theslider 116 based on a current location (or co-ordinates) of the slider116 on each of the tubes. Further, the stepper motor 118 may communicatethe incorrect position of the slider 116 to the control board 132. Thecontrol board 132 may verify the incorrect position of the slider 116 bycomparing the incorrect position to a programmed location of the slider116. In an exemplary embodiment, the programmed location of the slider116 is already preprogrammed or configured in the control board 132.Accordingly, the control board 132 may provide a command to the steppermotor 118 to move the slider 116 to a desired location based on thecomparison. This would help in error correction of the position of theslider 116 with respect to the programmed location of the slider 116.Moreover, the logs of error correction and position of the slider 116with respect to the programmed location may be captured/stored by thecontrol board 132 for error control and diagnostics purpose.

Although a limited number of tonnage profiles (i.e. 3 tonnage profiles)and slider positions (i.e. 3 positions) have been explained herein inthe specification for both the first mode, the second mode or in thethird mode, however, any number and any other possiblevariations/alterations in the tonnage profiles and slider positions arewithin the scope of this invention. Moreover, the movement/positioningof the slider on the tubes at several different positions is not onlylimited to centimeters or percentage, but any other possiblevariations/alterations for movement/positioning of the slider on thetubes at several different positions are within the scope of thispresent invention. As used herein, the definition of the terms “low”,“nominal” and “high” in the first mode as well as in the second mode mayvary from case to case and in each scenario. The choice of decidingwhether a difference between a pre-defined temperature threshold (forcooling or heating) and a current temperature inside the building/home128 is “low”, “nominal” and “high” resides with the control board 132.In an exemplary embodiment, the control board 132 may decide that adifference between a pre-defined temperature threshold (for cooling orheating) and a temperature inside the building/home 128 is “low” whensuch a temperature difference lies in the range of 2° Celsius to 8°Celsius. Similarly, the control board 132 may decide that a differencebetween a pre-defined temperature threshold (for cooling or heating) anda current temperature inside the building/home 128 is “nominal” whensuch a temperature difference lies in the range of 9° Celsius to 20°Celsius. Likewise, the control board 132 may decide that a differencebetween a pre-defined temperature threshold (for cooling or heating) anda current temperature inside the building/home 128 is “high” when such atemperature difference lies in the range of 21° Celsius to 35° Celsius.It is to be noted that the temperature ranges and the pre-definedtemperature threshold (for cooling or heating) provided herein areexemplary and any other possible variations/alterations in thetemperature ranges as well as the defined temperature threshold arewithin the scope of this invention.

FIG. 4A depicts an exemplary first position of a slider 116 for a firsttonnage profiles in a first mode. As explained in FIG. 2 and Table 1above, when the reversing valve 102 operates in the first mode, theslider 116 may be positioned at a first position in the first tonnageprofile. As can be seen in FIG. 4A, in the first mode of the reversingvalve 102, the slider 116 may be positioned on the third tube 112 andthe fourth tube 114 at the first position such that each tube (i.e. thefirst tube 106, the second tube 110, the third tube 112 and the fourthtube 114) have an opening of 12 millimeters to pass the refrigerant.

FIG. 4B depicts an exemplary second position and third position of aslider 116 for a second or third tonnage profiles in a first mode. Asexplained in FIG. 2 and Table 1 above, when the reversing valve 102operates in the first mode, the slider 116 may be positioned at a secondposition and/or a third position in the second tonnage profile and/orthird tonnage profile. As can be seen in FIG. 4B, in the first mode ofthe reversing valve 102, the slider 116 may be positioned on the thirdtube 112 and the fourth tube 114 at the second position and/or the thirdposition such that first tube 106 has an opening of 12 millimeters andother tubes (i.e. the second tube 110, the third tube 112 and the fourthtube 114) have an opening of 17.21 millimeters in order to pass therefrigerant.

FIG. 4C depicts an exemplary first position of a slider 116 for a firsttonnage profiles in a second mode or a third mode. As explained in FIG.3 and Table 2 above, when the reversing valve 102 operates in the secondmode or the third mode, the slider 116 may be positioned at a firstposition in the first tonnage profile. As can be seen in FIG. 4C, in thesecond mode or the third mode of the reversing valve 102, the slider 116may be positioned on the second tube 110 and the third tube 112 at thefirst position such that each tube (i.e. the first tube 106, the secondtube 110, the third tube 112 and the fourth tube 114) have an opening of12 millimeters to pass the refrigerant.

FIG. 4D depicts an exemplary second position and third position of aslider 116 for a second or third tonnage profiles in a second mode or athird mode according to an exemplary embodiment of the invention. Asexplained in FIG. 3 and Table 2 above, when the reversing valve 102operates in the second mode or third mode, the slider 116 may bepositioned at a second position and/or a third position in the secondtonnage profile and/or third tonnage profile. As can be seen in FIG. 4D,in the second mode or the third mode of the reversing valve 102, theslider 116 may be positioned on the second tube 110 and the third tube112 at the second position and/or the third position such that firsttube 106 has an opening of 12 millimeters and other tubes (i.e. thesecond tube 110, the third tube 112 and the fourth tube 114) have anopening of 17.21 millimeters in order to pass the refrigerant.

FIG. 5 depicts a flowchart outlining the features of the invention in anexemplary embodiment of the invention. The method flowchart 500describes a method for positioning a slider 116 of a reversing valve 102in heat pump/s. The method flowchart 500 starts at step 502.

At step 504, a control board 132 of system 200 or system 300 may receivea command from a thermostat 130 for operating a reversing valve 102 in afirst mode, a second mode or a third mode. The reversing valve 102 mayhave a first surface 104 and a second surface 108. Further, thereversing valve 102 may comprise a first tube 106, a second, tube 110,and a third tube 112, and a fourth tube 114.

At step 506, the control board 132 of the system 200 or the system 300may determine a tonnage profile for refrigerant to flow in the reversingvalve 102 as discussed in FIG. 2 and FIG. 3 above. Further, therefrigerant may flow in a first flow in the first mode as explained inFIG. 2 above or in a second flow in the second mode or in the third modeas explained in FIG. 3 above.

At step 508, the control board 132 of the system 200 or the system 300may communicate the command and the tonnage profile for refrigerant to astepper motor 118.

At step 510, the stepper motor 118 of the system 200 or the system 300may linearly move a lead screw 120 by the stepper motor 118 based on thecommand and the tonnage profile to position a slider 116. In specific,the slider 116 may be positioned on the second tube 110 and the thirdtube 112 in the second mode or on the second tube and the third tube inthe third mode as explained in FIG. 3 above or may be positioned on thethird tube 112 and the fourth tube 114 in the first mode as explained inFIG. 2 above. Then, the method flowchart 500 may end at 512.

The present invention is applicable to various fields such as, but notlimited to, hospitality industry, museums, libraries, colleges,universities, hospitals, offices and any such building that is wellknown in the art and where the heat pump/s having the reversing valve isused.

The order of execution or performance of the operations in examples ofthe invention illustrated and described herein is not essential, unlessotherwise specified. That is, the operations may be performed in anyorder, unless otherwise specified, and examples of the invention mayinclude additional or fewer operations than those disclosed herein. Forexample, it is contemplated that executing or performing a particularoperation before, contemporaneously with, or after another operation iswithin the scope of aspects of the invention.

When introducing elements of aspects of the invention or the examplesthereof, the articles “a,” “an,” “the,” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Theterm “exemplary” is intended to mean “an example of” The phrase “one ormore of the following: A, B, and C” means “at least one of A and/or atleast one of B and/or at least one of C”.

Having described aspects of the invention in detail, it will be apparentthat modifications and variations are possible without departing fromthe scope of aspects of the invention as defined in the appended claims.As various changes could be made in the above constructions, products,and methods without departing from the scope of aspects of theinvention, it is intended that all matter contained in the abovedescription and shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense.

Although the subject matter has been described in language specific tostructural features and/or acts, it is to be understood that the subjectmatter defined in the appended claims is not necessarily limited to thespecific features or acts described above. Rather, the specific featuresand acts described above are disclosed as examples of implementing theclaims and other equivalent features and acts are intended to be withinthe scope of the claims.

What is claimed is:
 1. A system comprising: a reversing valve adapted tooperate in a first mode, a second mode or a third mode, the reversingvalve comprises a first tube, a second tube, a third tube, and a fourthtube; a control board adapted to: receive a command for operating thereversing valve in the first mode, the second mode or the third mode;determine a tonnage profile for refrigerant to flow in the reversingvalve, the refrigerant flows in a first flow in the first mode, in asecond flow in the second mode or in the second flow in the third mode;and communicate the command and the tonnage profile for the refrigerantto a stepper motor; and the stepper motor adapted to: linearly move alead screw based on the command and the tonnage profile to position aslider on the second tube and the third tube in the second mode or onthe third tube and the fourth tube in the first mode or on the secondtube and the third tube in the third mode.
 2. The system of claim 1,wherein the tonnage profile for refrigerant is determined based on atemperature defined by a user.
 3. The system of claim 1, wherein theslider is variably positioned at a first position for a first tonnageprofile, at a second position for a second tonnage profile and/or at athird position for a third tonnage profile.
 4. The system of claim 1,wherein the stepper motor is adapted to perform a first number of stepsfor positioning the slider at a first position, a second number of stepsfor positioning the slider at a second position and/or a third number ofsteps for positioning the slider at a third position.
 5. The system ofclaim 1, wherein the stepper motor is adapted to determine an incorrectposition of the slider based on a current location of the slider,wherein the control board is adapted to verify the incorrect position ofthe slider with respect to a programmed location of the slider and isadapted to provide a command to the stepper motor to move the slider toa desired location.
 6. The system of claim 1, wherein the lead screw islinearly moved in an inward direction in the second mode or the thirdmode to position the slider on the second tube and the third tube. 7.The system of claim 1, wherein the lead screw is linearly moved in anoutward direction in the first mode to position the slider on the thirdtube and the fourth tube.
 8. The system of claim 1, wherein the firstmode is a heating mode, the second mode is a cooling mode and the thirdmode is a defrost mode.
 9. The system of claim 1, wherein the first tubeis a compressor discharge tube, wherein the first tube is positioned ata first surface of the reversing valve.
 10. The system of claim 1,wherein the second tube, the third tube, and the fourth tube arepositioned at a second surface of the reversing valve.
 11. The system ofclaim 1, wherein the second tube acts as a condenser tube, the thirdtube acts as a compressor return tube, and the fourth tube acts as anevaporator tube in the first mode.
 12. The system of claim 1, whereinthe second tube acts as an evaporator tube, the third tube acts as acompressor return tube, and the fourth tube acts as a condenser tube inthe second mode and/or in the third mode.
 13. The system of claim 1,wherein the second tube is connected to an indoor unit and the fourthtube is connected to an outdoor unit in the first mode, in the secondmode and/or in the third mode.
 14. The system of claim 1, wherein therefrigerant flows from a compressor to the first tube, from the firsttube to the second tube and from the second tube to an indoor unit inthe first flow.
 15. The system of claim 1, wherein the refrigerant flowsfrom a compressor to the first tube, from the first tube to the fourthtube and from the fourth tube to an outdoor unit in the second flow. 16.The system of claim 1, wherein the slider is a C-shaped slider or aU-shaped slider.
 17. A method comprising: receiving, by a control board,a command for operating a reversing valve in a first mode, a second modeor a third mode, the reversing valve comprises a first tube, a secondtube, a third tube, and a fourth tube; determining, by the controlboard, a tonnage profile for refrigerant to flow in the reversing valve,the refrigerant flows in a first flow in the first mode, in a secondflow in the second mode or in the second flow in the third mode;communicating the command and the tonnage profile for refrigerant to astepper motor; and linearly moving a lead screw by the stepper motorbased on the command and the tonnage profile to position a slider on thesecond tube and the third tube in the second mode or on the third tubeand the fourth tube in the first mode or on the second tube and thethird tube in the third mode.
 18. The method of claim 17, wherein theslider is variably positioned at a first position for a first tonnageprofile, at a second position for a second tonnage profile and/or at athird position for a third tonnage profile.
 19. The method of claim 17wherein the lead screw is linearly moved in an inward direction in thesecond mode or in the third mode to position the slider on the secondtube and the third tube and the lead screw is linearly moved in anoutward direction in the first mode to position the slider on the thirdtube and the fourth tube.
 20. The method of claim 17, wherein the firstmode is a heating mode, the second mode is a cooling mode and the thirdmode is a defrost mode.